Oral polio vaccine
What is Oral polio vaccine?
Two polio vaccines are used throughout the world to combat poliomyelitis (or polio). The first was developed by Jonas Salk through the use of HeLa cells and first tested in 1952. Announced to the world by Dr Thomas Francis Jr. on 12 April 1955, it consists of an injected dose of inactivated (dead) poliovirus. An oral vaccine was developed by Albert Sabin using attenuated poliovirus. Human trials of Sabin's vaccine began in 1957, and it was licensed in 1962. There is no long term carrier state for poliovirus in immunocompetent individuals, polioviruses have no non-primate reservoir in nature (although they have been induced in transgenic mice), and survival of the virus in the environment for an extended period of time appears to be remote. Therefore, interruption of person to person transmission of the virus by vaccination is the critical step in global polio eradication. The two vaccines have eradicated polio from most countries in the world, and reduced the worldwide incidence from an estimated 350,000 cases in 1988 to just 223 cases in 2012.
In November 2013, the World Health Organization announced a polio outbreak in Syria. In response, the Armenian government put out a notice asking Syrian Armenians under age 15 to get the polio vaccine. It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system.